package com.yoso.core.util;

import lombok.SneakyThrows;
import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class AesEncryptUtil {


    private static final String KEY = "zhelixie16weimim";
    private static final String IV = "bixushigyao16wei";

    @SneakyThrows
    private static Cipher getInstance() {
       return Cipher.getInstance("AES/CBC/NoPadding");
    }


    /**
     * 加密
     * @param data 明文
     * @return {@link String }
     * @author shizejin
     * @date 2023/12/01 14:36
     */
    public static String encrypt(String data) {
        return AesEncrypt(data, KEY, IV);
    }

    /**
     * 解密数据
     * @param data 密文
     * @return {@link String }
     * @author shizejin
     * @date 2023/12/01 14:36
     */
    public static String decrypt(String data) {
        return AesDecrypt(data, KEY, IV);
    }

    /**
     * @param data 明文
     * @param key  密钥，长度16
     * @param iv   偏移量，长度16
     * @return 密文
     * @Description AES算法加密明文
     */
    private static String AesEncrypt(String data, String key, String iv) {
        try {
            //AES/CBC/NoPadding
            Cipher cipher = getInstance();
            int blockSize = cipher.getBlockSize();
            byte[] dataBytes = data.getBytes();
            int plaintextLength = dataBytes.length;
            if (plaintextLength % blockSize != 0) {
                plaintextLength = plaintextLength + (blockSize - (plaintextLength % blockSize));
            }
            byte[] plaintext = new byte[plaintextLength];
            System.arraycopy(dataBytes, 0, plaintext, 0, dataBytes.length);
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            // CBC模式，需要一个向量iv，可增加加密算法的强度
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);
            byte[] encrypted = cipher.doFinal(plaintext);
            // 加密后直接转string可能乱码，用BASE64做转码。
            return encode(encrypted).trim();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * @param data 密文
     * @param key  密钥，长度16
     * @param iv   偏移量，长度16
     * @return 明文
     * @Description AES算法解密
     */
    private static String AesDecrypt(String data, String key, String iv) {
        try {
            //先用base64解密
            byte[] encrypted1 = decode(data);
            //AES/CBC/NoPadding
            Cipher cipher = getInstance();
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            IvParameterSpec ivspec = new IvParameterSpec(iv.getBytes());
            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original);
            return originalString.trim();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 编码
     *
     * @param byteArray
     * @return
     */
    public static String encode(byte[] byteArray) {
        return new String(new Base64().encode(byteArray));
    }

    /**
     * 解码
     *
     * @param base64EncodedString
     * @return
     */
    private static byte[] decode(String base64EncodedString) {
        return new Base64().decode(base64EncodedString);
    }

}
